The type of support that we are concerned with must be capable of supporting a fuse or other electrical device in a position where electrical clearance distances about the fuse or other electrical device are sufficient to withstand thousands of volts, must be readily adaptable to use in electrical apparatus of many different designs and configurations, must be capable of effectively supporting fuses or other electrical devices having a wide variety of different tube diameters, and must be durable enough to successfully withstand without damage the shocks and other mechanical stresses produced by shipping, installation, transportation, and use of the electrical apparatus.
Prior supports intended for such applications that we are aware of have been subject to one or more of the following disadvantages. They have not been readily usable with fuses or other electrical devices having different fuse/electrical device tube diameters. They have been unduly expensive both to fabricate and to install in electrical apparatus. They have not readily lent themselves to a variety of installations which require different orientations of the tube with respect to the supporting structure of the electrical apparatus. They have not been able to successfully withstand severe mechanical stresses such as might result from inadvertent dropping of the electrical apparatus through a distance of one foot onto a concrete floor. In under-oil installations, they have not been capable of withstanding without significant degradation of their mechanical properties exposure to hot oil for the prolonged expected life-times of the electrical apparatus.